Tidy up header
Tidy up header

dpshelio/openastronomy.github.io,dpshelio/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,dpshelio/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,Cadair/openastronomy.github.io,Cadair/openastronomy.github.io,OpenAstronomy/openastronomy.github.io,Cadair/openastronomy.github.io